HELMET TRACKING SYSTEM(HTS)

Group 8Andrés F. Suárez (EE)Brian Maldonado (EE)

Rígel Jiménez (EE)

Motivation

HTS

• According to the National Highway Traffic Safety Administration (NHTSA), there were over 9 million motorcycles registered in 2012 in the US.

HTS

• Unfortunately, the basic motorcycle lacks some technological features available in other transportation vehicles.

HTS

• The HTS system is about to change this because it will significantly enhance the motorcycle riding experience, by adding:

BluetoothCapabilities

Tracking Helmet location

24/7

Ability to text an emergency

contact

HTS

Goals and Objectives

Adding electrical components to the helmet

without significantly increasing the weight.

Keeping the helmet as spacious as it was

originally, even though it will now have the

electronic components.

Being able to synchronize the helmet to a

cell phone.

Implementing an accelerometer to the

helmet.

The system will be able to send text

messages.

Specifications

COMPONENT PARAMETER DESIGN SPECIFICATION

Battery Current Draw Less than 100 mA

Bluetooth Minimum Range 3 meters

GPS Accuracy 10 meters

GPS Acquisition time Less than 35 sec

Accelerometer Sensitivity Less than 20 mg/LSB

GSM Frequency Band 800 MHz or greater

GSM SMS length More than 90 characters

Helmet Additional Weight Less than 300 grams

Helmet Tracking System (HTS)

Bluetooth Module

RN-52 Bluetooth Audio Module Wireless communication used to connect the HTS

system to a cell phone (Supports iAP profile)

Bluetooth 3.0

class 2 Audio Module

UART console interfaces

Operation range: 10 meters (33 feet)

Supplied voltage: 3.0 ~ 3.6 V DC

Dimensions: 26.0 x 13.5 x 2.7 mm

Frequency band: 2.4 ~ 2.48 GHz

Maximum Data Rate: 3Mbps

Embedded Stack Profiles: A2DP, AVRCP

Built-in Antenna

Price: $ 24.95

RN-52

APPLICATIONS

High-quality, 2-channel audio streaming.

Wireless stereo headsets.Wireless speakers. Intercom push-to-talk audio

connectionAutomotive hands free audioRemote control for media

player.Computer accessories

Accelerometer Module

ADXL345 AccelerometerFEATURES

Voltage Supply 1.8V to 3.6V

Current Consumption 25 to 130µA at 2.5V

Resolution 10-bit at every g-range

Serial Communication SPI or I²C

Sensitivity ±2g 3.9mg/LSB, ±4g 7.8mg/LSB, ±8g 15.6mg/LSB, ±16g 31.2mg/LSB

Number of Axes 3-Axis

Dimension 3mm x 5mm x 1mm

Price $ 14.95

Accelerometer Registers and Functions

Registers8-bit register addresses ranging from 0x00 to 0x39Sets the specs for the interrupts and contains serial, and bandwidth

selection.Contains a total of 14 different interrupt functions.

Interrupt functions usedSelf Test Tests the electrical and mechanical parts for proper

function

Single Tap Interrupt is set when a single acceleration event passes acceleration and time threshold.

ADXL345 Accelerometer

𝑆𝑐𝑎𝑙𝑒=2(𝑔𝑓𝑜𝑟𝑐𝑒)28𝑏𝑖𝑡𝑠

→ 8𝑔256 𝑏𝑖𝑡𝑠=0.03125 𝑔/𝑏𝑖𝑡

Threshold Calculation:

4 g256 bits converted to HEX = FF

GPS Module

LS20031 GPS ModuleFEATURES

66 Channel – 5 Hz GPS Receiver

57600 bps TTL serial interface

3.3 V at 41 mA

Fast Time to first fix at low signals

LED indicator for fix or no fix

Acquisition Time : Cold Start 35 s Hot Start < 2sDimensions: 30 x 30 mm

Position Accuracy: 2.5 to 3 m

Uses NMEA protocol

Built-in micro battery to preserve system data for fast satellite acquisitionBuilt-in Antenna

Price: $ 59.95

LS20031 GPS Pin Assignment and Descriptions

Pin # Name Type Description

1 VCC P Power input

2 RX I Data Input (TTL level)

3 TX O Data Output (TTL level)

4 GND P Ground

5 GND P Ground

GSM Module

SM5100B GSM ModuleAPPLICATION:

Sends SMS messages with corresponding GPS coordinates.

FEATURES:

Dimensions: 35.0 x 39.0 x 2.9mm. Power: 3.3 – 4.2 V. Nominal 3.6 V. Current consumption: <100 μA when

module is off; and 2 mA in Sleep mode. Quad-band GSM. Frequency Bands: 900,850,1800,1900 MHz. Supports UART interfaces. Supports SIM (Auto Recognize). Soldered connection for antenna. LED to notify network status. Price: $59.95

SM5100B Functional Block Diagram

MCU

Microcontroller Selection

Microcontroller MSP430 ATmega1280 Atmega328Operating Voltage 3.3 V 5 V 5 V

Digital I/O Pins 14 54 (15 being PWM)

14 (6 being PWM output)

Analog Input Pins 6 16 6

Flash Memory 16 KB 128 KB 32 KB

SRAM 1 KB 8 KB 2 KB

EEPROM N/A 4 KB 1 KB

Clock Speed 16 MHz 16 MHz 16 MHz

ATMEL ATmega328

Primary means of control between system and subsystem peripherals.

Soft Serial Library included to communicate with multiple devices.

SPECIFICATIONS

1.8-5.5V Operating Range

Up to 20MHz processing speed

32kB Flash Memory & 1kB EEPROM

2kB Internal SRAM

8 Channel 10-bit ADC

Serial USART/SPI/2-wire I2C Interface

23 IO lines

Price: $ 4.50

ATMEL ATmega328

Battery

HTS Power Source

SPECIFICATIONS

Voltage Range between 3.0 to 4.2V

Average Voltage of 3.7 V

Capacity of 1.8Ah @ C/5 Rate @ 23°C±2°C

Energy Density 146Wh/kg, 317Wh/l

Weight 46 grams

Recommended charge rate is 900mA to 4.2V in a temperature range of 0°C to 45°C

Price: $ 29.95 Ultralife Lithium-Ion Battery 1800 mAh

HTS Power SourceHelmet Modules Power Consumption

Modules Active mode Sleep mode

ADXL345 145 µA 40 µA SM5100B

GSM/GPRS 200 mA 2mA

LS20031 GPS 29 mA 2mA

Bluetooth 30 mA --

ATmega328 0.3 mA 0.8 µA

All devices will be in sleep mode during operation except for the Bluetooth.

HTS Recharge Circuit

Lithium Ion/Polymer Batteries require special charging

If not charged the proper way it could ruin the battery

Lithium Ion/Polymer USB Battery Charger IC - MAX1555

External Supply of 3.7V to 7V Will recharge battery through USB

connection Max current charge of 300 mA

HTS EagleCAD Schematic

HTS PCB Design

Dimensions: 3.39 in X 3.08 in Price: $37.5

Scenario 1- Reporting an Accident

Accelerometer• Threshold passed• Sends Interrupt to

Microcontroller

Microcontroller• Wakes up GPS, GSM to

full active mode

GPS• Retrieves location and

sent to the microcontroller.

Decode• Micro decodes NMAE

packet into latitude and Longitude

GSM• Receives coordinates

with message• Sends SMS to

Emergency Contact

Scenario 2 – Respond from Emergency Contact

This Scenario follows the same steps as scenario 1 with added functions.

Emergency Response• Receives emergency

text from HTS.

Bluetooth• Can receive Phone

Call, like OnStar

Assess• If able to receive call

can inform situation, if not WCS assumed.

Distribution of Work Load

Rígel Andres BrianMCU X

Software X X

Bluetooth Module X

GPS Module X

GSM Module X X

Accelerometer Module X

Battery and Recharge X

Milestone

Total

Parts

Testing

Prototyping

Design

Research

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

BudgetItem Description Supplier # Units Cost66 Channel LS20031 GPS 5Hz Receiver  Sparkfun 1 $59.95SIM Socket  Sparkfun 1 $0.95SM5100B Mating Connector  Sparkfun 1 $2.95Cellular Shield with SM5100B  Sparkfun 1 $99.95Quad-band Cellular Duck Antenna SMA  Sparkfun 1 $7.95Arduino Uno - R3  Sparkfun 1 $29.95Rn-52 Bluetooth Audio Module  Sparkfun 1 $24.95Battery Charger  Sparkfun 1 $1.95Lithium Ion Battery 1800 mAh  Sparkfun  1 $11.95USB Mini-B connection  Sparkfun 1 $1.50USB Mini-B Cable  Sparkfun 1 $3.95ON/OFF switches  Sparkfun 2 $1.00

LEDs  Sparkfun 3 $1.20

ADXL345 Sparkfun 1 $14.95

Atmega328pMicrocontroller Pros 2 $9.00

RN-52 Evaluation BoardMicrochip Technology 1 $186.93

PCB 4pcb.com 1 $37.50Total $519.58

Difficulties

Getting both audio input and output from the Bluetooth module.

Getting proper voltage to all the modules.

Soldering very small components.

Questions?